Re: Do ipsec vendors care about privacy?

[Antonio Forzieri <antonio.forzieri@cefriel.it>]

Hugo Krawczyk wrote:
> A couple of messages in this thread remind us that the WG decided
> that protecting the responder's identity from active attacks is preferable
> to protecting I's identity from such attacks.  That's true, and I do NOT
> suggest to change that decision in the general case. 
One issue, I think, we have to consider is that when we are using EAP 
authentication we are no longer protecting IDr. Even if in a previous 
message I state that it is not so crucial, i think that we can do 
something to ensure a grade of protection on IDr at no cost.

What I was thinking about is:

Supposing that the responder can send EAP(Request,MD5) (for exaple) 
without knowing IDi. In that case to ensure a grade of protection on IDr 
we can force the use of IDr in message 3. If the iniziator doesn't know 
one of the IDr she cannot procede, and the responder will not expose his ID:

Initiator                          Responder
-----------                        -----------
HDR, SAi1, KEi, Ni         -->
                            <--    HDR, SAr1, KEr, Nr, [CERTREQ]
HDR, SK {[CERTREQ,] IDr,
          SAi2, TSi, TSr}   -->
                            <--    HDR, SK {IDr, [CERT,] AUTH,
                                            EAP }
                            ...
                            ...
As you can see Alice *MUST* use IDr, otherwise Bob will send her a Type 
7 NOTIFY MESSAGES (INVALID-SYNTAX).

What do the others think about?

-- 
------------------------------------------------
Antonio Forzieri
CEFRIEL - Politecnico di Milano
Tesista Area E-Service Tecnologies
Tel: 02-23954.334 - email: forzieri@cefriel.it
ICQ# 177683894
------------------------------------------------